beenull/ladybird
1
0
Fork 0
mirror of https://github.com/LadybirdBrowser/ladybird.git synced 2024-11-22 23:50:19 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions 6

LibSoftGPU: Use correct position for vertex_to_light

Browse source 
The spec has a few stipulations on what this value should actually be,
and hence we should follow it accordingly.
This commit is contained in:
Jesse Buhagiar 2022-01-15 13:40:15 +11:00 committed by Idan Horowitz
parent 38fc7361ca
commit fc8dd0bf68
Notes: sideshowbarker 2024-07-17 20:42:09 +09:00 
Author: https://github.com/Quaker762
Commit: https://github.com/SerenityOS/serenity/commit/fc8dd0bf68f
Pull-request: https://github.com/SerenityOS/serenity/pull/11905
Reviewed-by: https://github.com/BertalanD
Reviewed-by: https://github.com/IdanHo ✅
Reviewed-by: https://github.com/gmta
Reviewed-by: https://github.com/sunverwerth ✅
1 changed files with 23 additions and 5 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

28
Userland/Libraries/LibSoftGPU/Device.cpp
View file

@ -807,19 +807,37 @@ void Device::draw_primitives(PrimitiveType primitive_type, FloatMatrix4x4 const&
if (!light.is_enabled)
continue;
FloatVector4 vertex_to_light;
// We need to save the length here because the attenuation factor requires a non
// normalized vector!
auto sgi_arrow_operator = [](FloatVector4 const& p1, FloatVector4 const& p2, float& saved_length) {
if ((p1.w() != 0.0f) && (p2.w() == 0.0f)) {
saved_length = p2.length();
return (p2 / saved_length).xyz();
} else if ((p1.w() == 0.0f) && (p2.w() != 0.0f)) {
saved_length = p2.length();
return -(p1 / saved_length).xyz();
} else {
// FIXME: The OpenGL 1.5 spec says nothing about the case where P1 and P2 BOTH have a w value of 1, which would
// then mean the light position has an implicit value of (0, 0, 0, 0). This doesn't make any logical sense, and it most likely
// a typographical error. Most other GL implementations seem to just fix it to the distance from the vertex to the light, which
// seems to work just fine.
// If somebody with more insight about this could clarify this eventually, that'd be great.
auto distance = (p2 - p1);
saved_length = distance.length();
return (distance / saved_length).xyz();
}
};
float vector_length = 0.0f;
FloatVector3 vertex_to_light = sgi_arrow_operator(vertex.eye_coordinates, light.position, vector_length);
// Light attenuation value.
float light_attenuation_factor = 1.0f;
if (light.position.w() != 0.0f) {
vertex_to_light = light.position - vertex.eye_coordinates;
auto const vertex_to_light_length = vertex_to_light.length();
auto const vertex_to_light_length_squared = vertex_to_light_length * vertex_to_light_length;
light_attenuation_factor = 1.0f / (light.constant_attenuation + (light.linear_attenuation * vertex_to_light_length) + (light.quadratic_attenuation * vertex_to_light_length_squared));
vertex_to_light = vertex_to_light / vertex_to_light_length;
} else {
vertex_to_light = light.position.normalized();
}
// Spotlight factor